Adapter and method of use



March 14, 1967 R. MATRONE ADAPTER AND METHOD OF USE Filed Jan. '7, 1965 'FIG.I.

INVENTOR RAYMOND MATRONE ATTORNEYS! United States Patent 3,308,548 ADAPTER AND METHOD OF USE Raymond Matt-one, 3419 Asheville St., Philadelphia, Pa. 19136 Filed Jan. 7, 1965, Ser. No. 424,152 2 Claims. (Cl. 33-181) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to an adapter and, more particularly, to an adapter for and method more easily setting the contact points of an automotive distributor.

In attaining the efficient operation of an automotive engine, obtaining an accurate functioning of the distributor and associated parts can be somewhat bothersome. Normally, the distributor cam must be precisely positioned, as by turning over the engine cam shaft to place the high points of the camming surface adjacent the cam follower to which the contact points are secured.

The primary object of the invention is to provide means for facilitating proper setting of distributor contact points.

Another object of the invention is to provide such means wherein it is insignificant what may be the angular position of the distributor cam.

In one aspect of the invention automotive distributor contact points are set relative to a polygonally-shaped distributor cam by placing an adapter upon the cam with one portion thereof supported by the cam and a second portion closely overhanging a camming surface of the cam, and predeterminedly adjusting the position of the contact points relative to the peripheral surface of the adapter second portion prior to securing the contact points in their predetermined position.

In another aspect of the invention the adapter one portion is provided with a transverse aperture for receiving the distributor cam rotor post and has a smooth face terminating in a straight line to overlie a polygonal cam surface and intersecting the aperture for abutting a side face of the cam, the adapter second portion being integral with the one portion at the straight line and of a relatively larger thickness, the adapter second portion being defined by a straight edge extending from the straight line normal to the smooth surface and by an outermost arcuate segmental surface that intersects the end points of the straight edge.

These and other objects, features and advantages will ecome apparent from the following description and ac companying drawings in which:

FIG. 1 is a plan view of a typical distributor arrangement embodying the principles of the invention.

FIG. 2 is a sectional view of the distributor cam and adapter taken along line 22 of FIG. 1.

Referring to FIG. 1, the polygonal-shaped distributor cam 11 (denoted by the equilateral hexagon configuration as employed on six-cylinder automobiles) has at each hexagon corner, high points 12 on the camming surface. In setting the distributor contact points 13, 14, one of the high cam points 12 normally is required to be aligned and in contact with the cam follower 15 extending from a contact point carrying arm 16 that is pivotally biased by means (not shown) toward the cam 11 or in a clockwise direction about its post 19. Proper setting of a second contact point carrying arm 17, which likewise is pivotally mounted about common post 19 as by adjusting screw 18, enables a predetermined spark gap to be provided between contact points 13 and 14 at the time each cylinder is fired. However, it is often a difficult or tedious task to properly position the distributor cam with one of its camming surface high points aligned with the cam follower.

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The adapter shown generally at 20 preferably is formed of metallic or other rigid material such that certain portions thereof are of precise predetermined dimensions. The adapter has a first portion 21 provided with a circularshaped transverse aperture 22 for closely receiving a mating circular rotor post 23 that extends upwardly from its integral connection with the central upper face of the polygonal cam 11. The portion 21 has a substantially fiat smooth lower surface 24 (FIG. 2) terminating in a straight line 25 (FIG. 1) for precisely overlying one side or edge of the polygonal camming surface, the surface 24 intersecting the transverse aperture 22 so as to be capable of abutting the upper surface 26 of the cam 11. Integral with the portion 21 at the straight line 25 is an adapter second portion 28 which has a relatively larger'thickness. The portions 21 and 28 have their upper surfaces located in a common horizontal plane, and the adapter second portion 28 projects downwardly below the surface 24. Portion 23 is defined by an inner flat or straight edge or surface 29 extending downwardly from straight line 25 normal to the smooth surface 24 and by an outermost arcuate segmental surface 30 which intersects the end points31, 32 of the straight edge and which has all points thereon radially equidistant from the center 33 of aperture 22. Thus, when the adapter is positioned upon cam 11 and its rotor post 23 with the straight edge 29 precisely abutting the predetermined one side of the camming surface, the arcuate surface 30 will throughout its peripheral edge represent high points 12 of the camming surface, thereby facilitating the setting of adjacent distributor contact points 13, 14 without rotationally pre positioning the cam 11.

With the distributor cap and rotor (both not shown) removed, the cam follower arm 16 can be manually depressed or moved counter-clockwise away from the cam 11 and the adapter 21) placed in position upon the cam and its rotor post with the adapter second portion 28 closely overhanging the selected one of the straight edges or sides of the camrning surface. The cam follower arm 16 is then released permitting the cam follower 15 to biasingly engage the adapter arcuate surface 3% With the use of predetermined feeler gauge means temporarily placed between contact points 13, 14, the adjusting screw 18 serves to secure the second contact carrying arm 17 in its properly adjusted position.

After again depressing arm 16, the adapter is removed from the rotor post 23 and the rotor and distributor cap are re-positioned for starting the engine to continue the timing test.

Various modifications, changes or alterations may be resorted to without departing from the scope of the invention as defined by the appended claims.

I claim:

1. An adapter for overlying a polygonal shaped automotive distributor cam and a central rotor post thereon to facilitate the setting of automotive distributor contact points, comprising a rigid body of homogeneous material having one portion provided with a transverse aperture for snugly receiving said post, said one portion having a substantially solid smooth face terminating in a straight line, said line adapted to overlie a predetermined surface portion of a polygonal cam in a co-planar relationship, and said smooth face intersecting said aperture for abutting a side face of said cam,

said rigid body having a second portion integral with said one portion at said straight line and of a thickness substantially larger than that of said one portion, said second portion being defined by a flat surface extending from said straight line normal to said smooth surface and by an outermost arcuate segmental surface intersecting the end points of said flat surface,

so constructed and arranged that when said adapter is accommodated by said earn and post with said flat surface precisely abutting the polygonal cam surface portion said arcuate surface will throughout its peripheral edge represent the high points of said cam surface, thereby facilitating the setting of adjacent ness substantially larger than that of said one portion, said second portion being defined by a flat surface extending from said straight line normal to said smooth surface and by an outermost arcuate segmental surface intersecting the end points of said flat surface, said arcuate' surface having a mid-point radially equidistant from the center of said aperture as are said end points,

distributor contact points without rotationally prepositioning said cam. 10 2 An adapter for overlying a polygonal shaped automotive distributor cam and a central rotor post thereon to facilitate the setting of automotive distributor contact points, comprising a rigid body of homogeneous material having one por- 15 tion provided with a transverse circular aperture for snugly receiving said post, said one portion having a substantially solid smooth face terminating in a straight line, said line adapter to overlie a predetermined surface portion of a polygonal cam in a co-planar relationship, and said smooth face intersecting said aperture for abutting said face of a so constructed and arranged that when said adapter is accommodated by said earn and post with said flat surface precisely abutting the polygonal cam surface portion said arcuate surface will throughout its peripheral edge represent the high points of said cam surface, thereby facilitating the setting of adjacent distributor contact points without rotationally prepositioning said cam.

References Cited by the Examiner UNITED STATES PATENTS 2,453,774 11/1948 Basista 33 1s1 2,838,842 6/1958 Hassler 33 1s1 side earn,

LEONARD FORMAN, Primary Examiner. said rigid body having a second portion integral with said one portion at said straight line and of a thick- 25 MATTHEWS, Assistant Examllwr- 

1. AN ADAPTER FOR OVERLYING A POLYGONAL SHAPED AUTOMOTIVE DISTRIBUTOR CAM AND A CENTRAL ROTOR POST THEREON TO FACILITATE THE SETTING OF AUTOMOTIVE DISTRIBUTOR CONTACT POINTS, COMPRISING A RIGID BODY OF HOMOGENEOUS MATERIAL HAVING ONE PORTION PROVIDED WITH A TRANSVERSE APERATURE FOR SNUGLY RECEIVING SAID POST, SAID ONE PORTION HAVING A SUBSTANTIALLY SOLID SMOOTH FACE TERMINATING IN A STRAIGHT LINE, SAID LINE ADAPTED TO OVERLIE A PREDETERMINED SURFACE PORTION OF A POLYGONAL CAM IN A CO-PLANAR RELATIONSHIP, AND SAID SMOOTH FACE INTERSECTING SAID APERTURE FOR ABUTTING A SIDE FACE OF SAID CAM, SAID RIGID BODY HAVING A SECOND PORTION INTEGRAL WITH SAID ONE PORTION AT SAID STRAIGHT LINE AND OF A THICKNESS SUBSTANTIALLY LARGER THAN THAT OF SAID ONE PORTION, SAID SECOND PORTION BEING DEFINED BY A FLAT SURFACE EXTENDING FROM SAID STRAIGHT LINE NORMAL TO SAID SMOOTH SURFACE AND BY AN OUTERMOST ARCUATE SEGMENTAL SURFACE INTERSECTING THE END POINTS OF SAID FLAT SURFACE, SO CONSTRUCTED AND ARRANGED THAT WHEN SAID ADAPTER IS ACCOMMODATED BY SAID CAM AND POST WITH SAID FLAT SURFACE PRECISELY ABUTTING THE POLYGONAL CAM SURFACE PORTION SAID ARCUATE SURFACE WILL THROUGHOUT ITS PERIPHERAL EDGE REPRESENT THE HIGH POINTS OF SAID CAM SURFACE, THEREBY FACILITATING THE SETTING OF ADJACENT DISTRIBUTOR CONTACT POINTS WITHOUT ROTATIONALLY PREPOSITIONING SAID CAM. 